Question 720476:  if the point (-2,-7) is on the terminal arm of N, an angle in standard position, what is the value of cos N? 
 Answer by lwsshak3(11628)      (Show Source): 
You can  put this solution on YOUR website! if the point (-2,-7) is on the terminal arm of N, an angle in standard position, what is the value of cos N? 
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The value of angles in standard positions is measured by their reference angles. 
The reference angle is the angle the terminal arm makes with the horizontal x-axis 
The reference angle is in quadrant III where tan>0 
The x-value(-2) represents the horizontal(cos) leg of the reference right triangle 
The y-value(-7) represents the vertical(sin) leg of the reference right triangle 
The hypotenuse=√(2^2+7^2)=√(4+49)=√53 
cosN=-2/√53≈-0.2747 
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